Neuro Bonus Class Lecture

motor unit

the functional unit of the peripheral neuromusclar system

what does a motor unit consist of?

anterior horn cell

nerve root

plexus

individual nerve fiber

neuromuscular junction

muscle fibers innervated by axon

A patient is presenting to the outpatient PT clinic for balance and gait training after developing weakness and paresthesia of their left LE. Which of the following should be examined if the PT is suspecting lumbar radiculopathy

a. assess individual muscles innervated by specific peripheral nerves and 2 point discrimination

b. assess deep tendon reflexes only

c. assess LE dermatomes and myotomes

d. perform cranial nerve screen

c. assess LE dermatomes and myotomes

C1-2 Myotome

cervical flexion

C3 myotome

cervical side flexion

C4 myotome

scapular elevation

C5 myotome

shoulder abduction

C6 myotome

elbow flexion

wrist extension

C7 myotome

elbow extension

wrist flexion

C8 myotome

thumb extension

T1 myotome

finger abduction

L1-2 myotome

hip flexion

L3

knee extension

L4 myotome

ankle dorsiflexion

L5 myotome

big toe extension

S1 myotome

ankle eversion and plantarflexion

hip extension

S2 myotome

knee flexion

S3 myotome

no specific test action

intrinsic foot muscles (except abductor hallucis)

C1 dermatome

vertex of skull

C2 dermatome

temple

forehead

occiput

C3 dermatome

entire neck

posterior cheek

temporal area

prolongation forward under mandible

C4 dermatome

shoulder area

clavicular area

upper scapular area

C5 dermatome

deltoid area

anterior aspect of entire arm to base of thumb

C6 dermatome

anterior arm

radial side of hand to thumb and index finger

C7 dermatome

lateral arm and forearm to index, long and ring finger

C8 dermatome

medial arm and forearm to long, ring and little fingers

T1 dermatome

medial side of forearm to base of little finger

T2 dermatome

medial side of upper arm to medial elbow

pectoral and midscapular areas

T3-6 dermatome

upper thorax

T5-T7 dermatome

costal margin

T8-T12 dermatome

abdomen and lumbar region

L1 dermatome

back

over trochanter and groin

L2 dermatome

back

front of thigh to knee

L3 dermatome

back

upper buttock

anterior thigh and knee

medial lower leg

L4 dermatome

medial buttock

lateral thigh

medial leg

dorsum of foot, big toe

L5 dermatome

buttock

posterior and lateral thigh

lateral aspect of leg

dorsum of foot

medial half of sole, first, second and third toes

S1 dermatome

buttock

thigh

leg posterior

S2 dermatome

buttock

thigh

leg posterior

S3 dermatome

groin

medial thigh to knee

S4 dermatome

perineum

genitals

lower sacrum

a patient presents with weak DF and toe extension on the R LE, and decreased sensation over webspace of 1st and 2nd digits. Which of the following would be an appropriate diagnosis for the patient?

a. deep fibular nerve neuropathy

b. L3 nerve root radiculopathy

c. obturator nerve neuropathy

d. L4 nerve root radiculopathy

a. deep fibular nerve neuropathy

radiculopathy definition

compression or irritation of a spinal nerve root

radiculopathy sit of lesion

near the spinal root (within intervertebral foramen)

radiculopathy sensory loss pattern

dermatomal

skin area supplied by one spinal root

radiculopathy motor weakness

myotomal patern

group of muscles from one root

radiculopathy reflex changes

root specific reflex loss

radiculopathy common causes

herniated disc

foraminal stenosis

spondylosis

trauma

radiculopathy pain characteristics

radiating

sharp

shooting pain following a dermatome

radiculopathy diagnostic tests

MRI spine

EMG shows paraspinal involvement

radiculopathy example

L5 radiculopathy - pain down lateral leg, weakness in great toe extension

neuropathy definition

damage or dysfunction of a peripheral nerve

neuropathy sit of lesion

along the nerve pathway beyond the root

neuropathy sensory loss pattern

peripheral nerve distribution

area supplied by that nerve

neuropathy motor weakness

in muscles supplied by the specific peripheral nerve

neuropathy reflexes changes

reflexes affected only if the involved nerve contributes to that reflex arc

neuropathy common causes

diabetes

entrapment (carpal/tarsal tunnel)

toxins

infection

vitamin deficiency

neuropathy pain characteristics

burning

tingling

numbness in nerve distribution (often distal, stocking-glove in polyneuropathy)

neuropathy diagnostic test

nerve conduction study shows slowed conduction in the affected nerve

neuropathy example

peroneal neuropathy

foot drop, sensory loss over dorsum of foot

Cervical Spine Nerve Root Involvement: Disc Herniation

pick level below

Cervical Spine Nerve Root Involvement: Stenosis

pick level below

Lumbar Spine Nerve Root Involvement: Disc Herniation

pick below level

Lumbar Spine Nerve Root Involvement: Stenosis

pick above level

superior gluteal nerve

L4-S1

superior gluteal nerve muscles affected

gluteus medius

gluteus minimus

tensor fascia latae

superior gluteal nerve movements impaired

hip abduction, flexion and internal rotation

Inferior Gluteal Nerve

L5-S2

Inferior Gluteal Nerve muscle affected

gluteus maximus

Inferior Gluteal Nerve movements impaired

hip extension

external rotation

sciatic nerve

L4-S3

sciatic nerve origination

sacral plexus

crosses through the greater sciatic foramen in the pelvis

sciatic nerve muscles affected

biceps femoris

adductor magnus

semimembranosus

semitendinosus

sciatic nerve muscles affected mnemonic

BASS

piriformis syndrome

due to abnormal shortening of the muscle compression and causing irritation at the nerve site

sciatica

herniated disc or bone spur that compresses the sciatic nerve and cause radiating pain

a patient presents to the outpatient clinic for gait training on an even surface and no assistive device. While performing gait training, the patient reports numbness and tingling on the medial malleolus of the R LE. Formal MMT revealed 5/5 strength for R LE. Which of the following findings would be expected while examining the patient?

a. common fibular nerve entrapment

b. disc herniation at level of L4-L5

c. sural nerve neuropathy

d. saphenous nerve entrapment

d. saphenous nerve entrapment

femoral nerve

L2-L4

femoral nerve MOI

upper femur or pelvis fractures

hip dislocation with reduction

forceps pressure during labor

femoral nerve muscle affected

quadriceps

pectineus

sartorius

femoral nerve sensory impairment: lateral femoral cutaneous

lateral thigh over ITB

femoral nerve sensory impairment: intermediate femoral cutaneous

anterior thigh

femoral nerve sensory impairment: medial femoral cutaneous

anteromedial thigh

femoral nerve sensory impairment: saphenous

medial femoral condyle

posterior medial lower leg

medial malleolus

tibial nerve

L4-S3

tibial nerve muscles mnemonic

GPS FLEXES TIBIA

tibial nerve muscles

gastrocnemius

plantaris

posterior tibialis

popliteus

soleus

flexor hallucis longus

flexor digitorum longus

tibial nerve sensory branch: medial plantar

medial foot sole over 1st,2nd,3rd and medial half of 4th digits

tibial nerve sensory branch: lateral plantar

lateral foot sole over lateral half of 4th toe and entire 5th digit

tibial nerve sensory branch: medial calcaneal

medial heel

tibial nerve sensory branch: sural

posterolateral lower leg

lateral border of the dorsum of the foot

lateral heel

Tarsal Tunnel Syndrome

entrapped under medial foot through adductor hallucis

tarsal tunnel syndrome symptoms

postermedial plantar foot

painful heel

pes cavus = pain

postural foot changes due to compression injury

pes planus

claw toes

pes planus

collapsed medial longitudinal arch marked by flat feet when WB

claw toes

MTP extension, PIP/DIP flexion

Common Peroneal Branches

superifical peroneal

deep peroneal

superficial peronal: sensory

anterolateral lower leg and dorsum of foot

superficial peronal: muscles

peroneus longus and brevis

superficial peronal: injury

decreased eversion strength

deep peronal: sensory

webspace between 1st and 2nd toes on dorsal surface of foot

paresthesia symptoms: hallmark sign of anterior compartment syndrome